The first cattle born to a cloned cow in Britain will this week be sold at public auction. The sale - at a cattle market outside Bristol - marks the opening of a new chapter in food technology in this country, say scientists.

They expect that Dundee Paradise, whose mother was the clone of a prize-winning Holstein cow, and her brother, Dundee Paratrooper, will be bought by breeders in the first step towards the creation of new generations of cattle in Britain.

The move has been hailed by many breeders who believe that cloned cattle offer the only effective prospect of continuing to provide top-quality meat at a time when the world faces shortages in supplies of key foodstuffs. Only the creation and use of genetically manipulated plants and animals can prevent this, it is argued.

'These animals will not be sold for meat,' said Simon Best, chairman of the BioIndustry Association. 'They will cost far too much for that. Instead they will be bought by other breeders to create offspring that will go on to help to improve Britain's livestock.'

Scientists now predict that beef burgers from clone-farmed cattle will soon be approved in the United States and that Europe will eventually give the go-ahead for the sale of cloned meat as well.

This prospect causes alarm among green groups, however, and the sale of Dundee Paradise and Dundee Paratrooper - whose mother was Vandyk-K Integ Paradise 2, a clone created from cells taken from the ear of a Holstein, a milking cow, in the US - may become the focus of protests by groups opposed to the creation of what they call 'Frankenstein' foods. They say the manipulation of animals in the laboratory could trigger unforeseen, potentially harmful changes to beef and other meats. This charge is vigorously rejected by scientists, however, and by bodies such as the Food Standards Agency and the European Food Safety Authority.

More to the point, cloned meat will become increasingly important, say scientists, as Britain strives to make its farms more environmentally friendly by reducing its use of nitrates and other harmful chemicals as well as its output of carbon dioxide and other greenhouse gases. In the case, of Dundee Paradise and Dundee Paratrooper, this has been done by creating a clone of a top milk-producing Holstein. Such animals mean that more milk can be generated on a farm without increasing use of fertilisers and fodder.

'Normally it takes generations to introduce new improved traits into cattle - by carefully cross-breeding different cows and bulls,' added Best. 'However, by creating a clone of an ideal animal, in this case one that is a top milk-producer, you have done it in a single generation. Thus you can make improvements to livestock, and to the nation's beef and milk, far more quickly than by using traditional breeding techniques.'

The only concern for UK scientists is the fact that the technology used to create the cattle was invented in Britain - by the team, led by Ian Wilmut and Keith Campbell, responsible for the cloning of Dolly the Sheep. But now virtually all commercial cloning work of livestock is done in the US, and farmers and breeders in Britain, as with Dundee Paradise and Dundee Paratrooper, have to buy from companies on the other side of the Atlantic.

In addition, news of the sale of the cattle - which are owned by Smiddiehill Holsteins, based at Albrighton, Shropshire - comes as ministers and their advisers are warning that significant food shortages could arise in Britain unless urgent moves are taken to ensure that the country adopts a sensible, balanced food policy. A national debate on the issue is urgently needed, they say.

The problem is that consumers expect cheap and plentiful meat, fruit, vegetables and groceries, yet their production causes harmful greenhouse gases and is unsustainable because of the UK's limited availability of land, oil and water, said Tim Lang, of the government's sustainable development commission (SDC). 'We've had an orgy of choice unparalleled in human history in the past 50 years, but many analysts agree that, unless there is fundamental change, food supply chains could even collapse,' said Lang, who is also professor of food policy at City University, London.

Suggested ways for transforming the attitudes of consumers and the food industry include rationing by putting up prices and encouraging supermarkets to stock a smaller range of identical products. But encouraging the public to behave differently is a complex process, added Lang. More than 30 per cent of people claim to care about companies' environmental and social records, for example, but only 3 per cent reflect these beliefs in their purchases.

'We are missing the point if we put all the onus of choice onto consumers,' said Lang. 'Choice is part of the problem, not the solution. Do you load responsibility on every consumer or do you constrain their choice? We can't ask consumers to spend 24 hours thinking about which of an aisle-full of nearly identical products to buy when so many are inappropriate - too high in carbon, for example.'

Instead, said Lang, policies need to be introduced that shape the choices consumers make. 'We all like to think we choose our diets but choice is already structured by history, price and policy.'

Production, distribution and consumption of food in Britain is responsible for around a fifth of total UK greenhouse gas emissions. The Stern report in 2006 said agriculture alone globally accounts for 31 per cent of emissions.

'The UK situation is being stressed not just by water and oil shortages but also land availability, labour skills and affordability,' said Lang, who is calling for a national debate about future policies to engage the public and how to transform consumption. 'We have to involve the public in this process of change.

'So far, expert debate is about the existence of problems and not enough is about involving the public,' said Lang, who will discuss the issue in early March in a speech at City University titled Food Security: Are we sleep-walking into a crisis?

'There are those who believe we can use hi-tech solutions to get out of the problem and others just believe markets will resolve it. But the key will be public acceptance. The paradox is that Britain was never better fed than during the Second World War, when rationing was in place. This was because the public saw its purpose; it didn't like it, but it accepted necessity. In a future crisis, rationing will be designed for sustainability, not just health and equity.'

Lang's call is supported by the Sustainable Consumption Roundtable - a joint initiative between the SDC and the National Consumer Council (NCC), which explores ways that the government can help create a shift to more sustainable lifestyles and is funded by the Department for Environment, Food and Rural Affairs and the Department for Business, Enterprise and Regulatory Reform .

'There is not enough evidence to suggest that consumers on their own are able to change mainstream product markets,' said Ed Mayo, chair of the Roundtable and chief executive of the NCC.

"'Choice editing" for quality and sustainability by regulators, retailers and manufacturers has been the critical driver towards more sustainable consumption. Early announcement of legislation to set minimum standards can also drive a virtuous cycle of rapid innovation and further choice editing,' he added.

A history of cloning

June 1995 The world's first cloned mammals, two lambs, are born at Roslin Institute, near Edinburgh.

5 July 1996 The most famous clone of them all, Dolly the Sheep, is born.

6 July 1998 Scientists in Japan say they have succeeded in cloning a cow.

August 2005 Korean scientists announce the first cloned dog, Snuppy.

November 2007 Oregon scientists announce the creation of the world's first cloned monkey embryos and extract stem cells from them, eventually growing them into heart and nerve cells.